In accordance with recent trends toward increased lightness of automobiles, demand for thermoplastic resins providing superior rigidity for automobile exterior components such as body panels, spoilers and the like has significantly increased. A large amount of filler can be added to a resin in order to impart a high degree of rigidity, improvements in rigidity, dimensional stability and heat resistance to the thermoplastic resin. Impact resistance, however, may be remarkably degraded and also the exterior appearance of an injection-molded product can deteriorate due to filler particles being not dispersed.
A linear acrylic impact reinforcing agent can be added to a thermoplastic resin to improve impact resistance of, for example, a polycarbonate resin. A linear acrylic impact reinforcing agent may improve impact resistance properties but can also cause delamination in an injection-molded product due to a reduction in compatibility between the polycarbonate resin and the acrylic impact reinforcing agent. Further, halo patterns may be formed in a surface of the injection-molded product.
Glass fiber can also be used to provide a resin having high degrees of rigidity and dimensional stability. The glass fiber, however, can significantly deteriorate the exterior appearance of an injection-molded product due to protrusion of glass fiber. Wollastonite or barium sulfate (BaSO4) can be used as filler to provide an injection-molded part with excellent exterior appearance. The injection-molded part, however, may not have sufficient dimensional stability and rigidity.